drugs to treat GERD, PUD, IBD and h.pylori Flashcards
what are the different treatment options for GERD
lifestyle modifications
antacids
surface agents
H2receptor antagonists (H2RAs)
proton pump inhibitors (PPI)
what is the MOA of Antacids
neutralize acid (raise pH)
what are the uses of antacids
mild, intermittent heartburn or reflux (<1 episode/week)
what is the PK of antacids
onset: 5 min
duration: 30-60 minutes
what are the types of Antacids
calcium hydroxide (tums, maalox)
aluminum hydroxide (mylanta, gaviscon)
magnesium hydroxide (mylanta, gaviscon)
what are the SE of calcium hydroxide antacids
constipation
hypercalcemia
alkalosis
acute or chronic renal injury
what are the SE of aluminum hydroxide antacids
constipation
hypophosphatemia
*caustion with renal failure
what are SE of magneisum hydroxide antacids
diarrhea,
hypermagnesemia
*caution with renal failure
what is the MOA of surface agents
coats esophageal/gastric mucosa, creates physical barrier between mucosa and acid
what are the uses of surface agents
short-term management of GERD symptoms (4-8 weeks for duodenal ulcer)
swallow after meals, avoid drinking/eating afterwards
what is the PK of surface agents
onset: 5 minutes
duration: 30-60 minutes
what are the types of surface agents
sucralfate
sodium alginate
bismuth
what are the SE of sucralfate
constipation
aluminum toxicity
*caution with: renal failure, DM
What is the MOA of H2RAs
blocks stimulation of gastric parietal cells by competing with histamine H2 receptor
what are the uses of H2RAs
GERD, dyspepsia, PUD
-less effective than PPI, may be useful as adjunct
-not effective for H/pylori
what is the PK of H2RAs
onset: 2 hours
Duration: 4-10 hours
what are H2RA durgs
cimetidine, famotidine
what are the SE of H2RAs
HA, dizziness, diarrhea, constipation
cimetidine: gynecomastia
prolonged use(>2yrs) may lead to B12 deficiency
what is the MOA of PPIs
block gastric H/K-ATPase, inhibiting gastric acid secretion
what is the uses of PPIs
GERD, dyspepsia, PUD, H.pylori
-most effective acid suppressing med
what is the PK of PPIs
onset: 1 hour
duration: ~24 hours
admin: 30-60 min before first meal of the day
what are the PPI medications
Omeprazole
Pantroprazole
Lansoprazole
Esomeprazole
what are the risks of PPIs
available for >25 yo. may double blinded RCTs over years have not supported initial safety concerns
longer term: malabsorption of some minerals and vitamins, increased risk of some diarrheal illnesses, bacterial pneumonia, acute interstitial nephritis (AIN), CKD, gastric polyps
what are the SE of PPIs
HA
nausea
abdominal pain
diarrhea
what are drug interactions with PPIs
decreased absorption of certain HIV protease inhibitors
increased concentration of digoxin, carbamazepine, theophylline; warfarin, diazepam, phenytoin
Increased MTX concentration/toxicity
decrease anti-platelet effect of Plavix
decrease absorption of PO iron
what is the Tx of PUD
avoid offending agents
anti-seretory agent (PPI) = mainstay of tx
test for and treat h.pylori if present
what is the tx regimen for H/pylori
2 week duration
Triple therapy: Clarithromycin + amoxicillin + PPI
Quadruple therapy: bismuth subsalicylate + tetracycline + metronidazole + PPI
what is the MOA for Busmuth
stimulates prostaglandin/mucous/bicarb production in the stomach
mild antimicrobial activity, specifically against H.pylori
reduces inflammation
what is the SE of bismuth subsalicylate
black stools, black tongue (reversible)
bismuth neurotocixity: encephalopathy, asepctic meningitis, seizures
what needs to be cautioned with bismuth use
other salicylates/ASA/NSAIDs
increased risk of bleeding
neurotoxicity
tinnitus
what is the MOA of Misoprostol
synthetic prostaglandin E1 analog. Prostaglandins inhibit acid secretion by reducing the ability of parietal cells to respond to histamine
what is the use of Misoprostol
prevention of NSAID-induced gastric ulcers
what is the PK of Misoprostol
onset: 30 min
duration: 3 hours
what are the SE of misoprotol
diarrhea
abd pain
HA
avoid with magnesium containing antacids
what are the contraindications with misoprotol
caution: can induce uterine contractions
BBW: contraindicated in pregnancy or women of childbearing age. may cause birth defects, premature birth, abortion, uterine rupture
what are the Prokinetic agents
Metoclopramide, doperidone, erythromycin
what is the MOA of Metoclopramide
dopamine antagonist (primarily). enhances upper GI tract response to Ach to enhance motility; increases colon motility and shortens transit time
what is the use of Metocloramide
gastroparesis, peristent GERD, N/V
can be useful for diabetic patients
short term use only given risk of TD: <12 weeks
what is the PK of Metoclopramide
onset: 30-60 min
duration: 1-2 hours
what are the SE of metoclopramide
drowsiness
dystonia
HA
what are the contraindications with metoclopramide
BBW: can cause tardive dyskinesia (irreversible)
CI: Gi hemorrhage, mechanical obstruction, perforation
what is the MOA of Domperidone
peripheral dopamine antagonist (does not cross BBB). increase esophageal peristalsis, gastric motility and gastric emptying; decreases small bowel transit time
what is the use of Domperidone
gastroparesis/motility disorders, N/V
-not available in US
what are the SE of Domperidone
HA, migraines, xerostomia
may increase prolactin levels -galactorrhea, gynecomastia
what is the MOA of erythromycin
macrolide antibiotic. Motilin agonist - increases gastric contractions (prokinetic)
what is the use of Erythromycin
gastroparesis (primarily used as antibiotic)
used for max 4 weeks duration d/t tachyphylaxis
what are the SE of erythromycin
cardiovascular arrhythmias, QTc prolongation
superinfection (C.diff)
major inhibitor of CYP3A4
myasthenia gravis - may exacerbate or cause symptoms
what is the MOA of Neostigmine
acetylcholinesterase inhibitor
what is the use of Neostigmine
acute colonic pseudo-obstruction (primarily used for M. gravis, also post-op bladder distention/urinary retention)
what are the SE of neostigmne
Cardiac arrhythmias - especially bradycardia
dizziness, drowsiness, diarrhea
*caution with CVD
what are the treatment options for IBD
flares: glucocorticoids, aminosalicylates(5-ASAs)
maintenacne: biologics, immunomodulatiors, aminosalicylates
what is the MOA of 5-ASAs
work topically on affected/inflamed areas of mucosa; anti-inflammatory and immunosuppresive activity
what is sulfasalazine and Mesalamine
aminosalicylate (5-ASA)
what is the use of 5-ASAs
generally used for mild-moderate UC (flares and maintenace) - can be used for mild colonic Crohn’s disease (distal)
what are the SE of Sulfasalzine
Nausea
HA
rash
arthralgia
bone marrow suppression
oligospermia in men (infertility) - reversible
what are the SE of Mesalamine
nausea
HA
diarrhea
abdominal pain
nephrotoxicity/interstitial nephritis - rare
what are the drug interactions iwth mesalamine
antacids, H2RAs, PPIs can diminish efficacy of mesalamine
what is the use of immunosuppresants
induce and maintain remission in both UC and Crohn’s. good for pts who can not maintain remission when steroids are tapered down/off, can help reduce steroid dose
-slow acting drug. can take ~3-6 montsh to observe effect
what are the immunosuppresant medicatiosn
Azathioprine, methotrexate, Adalimumab/ Infliximab
what is the SE of Azathioprine
N/V
bone marrow suppression (anemia, leukopenia, thrombocytopenia)
liver toxicity
what medications should be avoided with azathioprine
avoid with allopurinol (gout med) - leukopenia
what is the MOA of methotrexate
immunosuppressant, anti-inflammatory for IBD
one of first antineoplastic drug developed. acts as folate antagonist, inhibiting DNA syntheses, repair and cellular replication
what is the USE of methotrexate
induce and maintain remission of Crohn’s disease (less commonly used for UC)
what are the SE of methotrexate
diarrea
n/v
alopecia
bone marrow suppression
mucositis
severe possibly fatal skin reactions, SJS, TEN
what are BBW with methotrexate
severe toxic/fatal SE
hepatotoxicity
potentially fatal opporunisitic infections
lung disease
teratogen
what is the MOA of biologics
bind and sequester TNF to decrease inflammatory response
what is the use of biologics
maintenance for moderate to severe IBD (mostly for Crohns disease. infliximab also used for UC)
what are the biologic medications
Adalimumab/ Infliximab
what is the SE of infliximab
injection site reaction/infusion reaction
HA, abdominal pain, liver toxicity, heart failure, infections, URI
risk of infection worse with concomitant immunosuppression
no live vaccines while on therapy
what is the MOA of glucocorticoids
inhibits production of inflammatory cytokines and inhibit migration of inflammatory cells to affected area
what is the use of glucocorticoids
moderate-severe Crohn’s and UC; helpful in early tx and during flares
what are the common glucocorticoids we use with IBD
PO: prednisone/prednisolone : Budesonide/entocort
Rectal: hydrocortisone
